gss: SAnon - the Simple Anonymous GSS-API mechanism

Add support for SAnon, a simple key agreement protocol that provides no
authentication of initiator or acceptor using x25519 ECDH key exchange.
See doc/standardization/draft-howard-gss-sanon-xx.txt for a protocol
description.

lib/gssapi/sanon/context_time.c

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 1997 - 2003 Kungliga Tekniska Högskolan
+ * (Royal Institute of Technology, Stockholm, Sweden).
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "sanon_locl.h"
+
+OM_uint32 GSSAPI_CALLCONV
+_gss_sanon_context_time(OM_uint32 *minor,
+			gss_const_ctx_id_t context_handle,
+			OM_uint32 *time_rec)
+{
+    const sanon_ctx sc = (const sanon_ctx)context_handle;
+
+    *minor = 0;
+    *time_rec = GSS_C_INDEFINITE;
+
+    if (sc == NULL)
+	return GSS_S_NO_CONTEXT;
+
+    return GSS_S_COMPLETE;
+}